(1) Field of the Invention
This disclosure pertains to railway covered hopper cars and in particular to the roof and side plate section of the hopper cars.
(2) Description of the Prior Art
The prior art has shown a number of roof structures for increasing the volume of a hopper car while retaining the outside dimensions of the vehicle within the so-called clearance lines. Heretofore, a number of structures have been attempted including stepped roofs and rounded roof arrangements which combine with curved sides. While these prior designs have met with some limited success, there has been a continuing search for a simple, low cost structure which can be easily adapted to fit flat side hopper cars and which will not only increase the volumetric capacity, but will also provide a rigid structure which does not deflect excessively in transit and which has a long life span.